1. Field of the Invention
The present invention relates to a settling (permanent set in fatigue)preventing structure with a supporting plate arranged on a warping side of an elastic contact portion to prevent excess warping of the elastic contact portion of a female terminal.
2. Description of the Related Art
FIGS. 14-15 show a conventional settling preventing structure of a terminal disclosed in J-UM (Laid-Open)-7-42005.
As seen from FIG. 14, within a square cylindrical electric contact portion 57 of a female terminal 56, a supporting plate 60 is uprighted vertically from a bottom wall 59 on the lower side of an elastic contact piece 58 so that the tip of the supporting plate 60 is opposite to the lower surface of the elastic contact piece 58. When the elastic contact piece 58 is warped, the lower face of the elastic contact piece 58 is brought into contact with the tip of the supporting plate 60, thereby preventing excess warping of the elastic contact piece 58 and its settling.
Further, on both sides of the supporting plate 60, protrusions 61 are formed. On the side walls 62 of the electric contact portion 57, engagement holes 63 are formed so as to correspond to the protrusions 61. Since the protrusions 61 are engaged in the engagement hole 63, fall of the supporting plate 60 can be prevented. As shown in FIG. 15, even when a male terminal is inserted in the electric contact portion 57 so that it pries the elastic contact portion 58, the supporting plate 60 supports the elastic contact piece 58 to prevent its excess warping.
However, the above conventional structure has the following defect. Specifically, when the terminal 56 is miniaturized, the protrusions 61 of the supporting plate 60 have also a very small size so that the engagement force thereof is reduced greatly. Because of the excess weighting, the supporting plate 60 falls as indicated in arrow x. As a result, the elastic contact piece 58 warps excessively and may be settled permanently.
FIGS. 16-17 show another settling preventing structure for a terminal disclosed in J-UM(Laid-Open)-3-77382.
As seen from FIG. 16, within the electric contact portion 66 of a female terminal 65, a pair of supporting pieces 69 are horizontally cut out from both side walls 68 so that the upper end of each supporting piece 69 is opposite to the lower face of the elastic contact piece 67. When the elastic contact piece warps, the lower surface of the elastic contact piece 67 is brought into contact with the upper end of each supporting piece, thereby preventing excess warping of the elastic contact piece 67.
However, this structure has the following defect. As the terminal 65 is miniaturized, the side walls 68 and supporting plates 69 each has a reduced thickness to decrease the rigidity of the supporting plates. Therefore, as shown in FIG. 17, when the elastic contact piece 67 is pried excessively as a result that a prove pin 70 for checking conduction and a jig bar for releasing terminal engagement is inserted, a supporting piece 69 is deformed rearward or downward as indicated by arrow y and hence the elastic contact piece 67 is likely to be settled.
FIGS. 18-19 shows a settling preventing structure of a terminal disclosed in JP-A-9-35796.
As seen from FIG. 18, within an electric contact portion 72 of a female terminal 71, a front and a rear supporting plate 75 are uprighted vertically from a bottom wall 74 on the lower side of an elastic contact piece 73 so that the tip of each supporting plate 75 is opposite to the lower surface of the elastic contact piece 73. When the elastic contact piece 73 is warped, the lower face of the elastic contact piece 73 is brought into contact with the tip of the supporting plate 75, thereby preventing excess warping of the elastic contact piece 73 and its settling.
However, in this structure, as shown in FIG. 19, when the elastic contact piece 73 is subjected to excess load in a prying direction by a probe pin 76 or jig rod, the supporting plates 75 fall as indicated by arrow z and are deformed so that the elastic contact piece 73 is likely to be settled.